Over the last few years, we have invested heavily in Microsoft Graph to enable developers to access the rich data available in Microsoft 365. Microsoft Graph, along with OAuth 2.0, provides increased security and seamless integration with other Microsoft cloud services.
In August 2018, we announced that we were no longer going to actively invest in Exchange Web Services (EWS) APIs for Exchange Online. We also gave a strong recommendation to start migrating to Microsoft Graph for Exchange Online data access.
Today, we are announcing that we are going to remove the ability to create new EWS apps starting September 30, 2022. We are also announcing the deprecation of the 25 least used APIs of EWS for Exchange Online (as determined by the call volume into the service). We are deprecating these APIs to begin the process of reducing the surface area of the EWS protocol for maintenance and security purposes. Support for these APIs will no longer exist after deprecation.
The list of deprecated APIs is at the end of this post. We will introduce sunset headers in the response for these APIs that are marked for deprecation. As per our deprecation policy, we will decommission these APIs by March 31, 2022.
This set of deprecations is the first in a series of steps we will take as we sunset EWS for Exchange Online. Over time, we will identify additional APIs for deprecation when and where we see adequate parity with Microsoft Graph APIs.
EWS is a legacy API surface that has served us well, but no longer meets the security and manageability needs of modern app development. We strongly urge our ecosystem partners accessing Exchange Online data to migrate to Microsoft Graph APIs.
APIs scheduled for deprecation:
The Exchange Team and Microsoft Graph Team